This chapter presents a case study which involves an application of Human Factors Analysis and Classification System (HFACS) to the analysis of Australian General Aviation (GA) incidents. The HFACS analysis involved the use of an expert panel of experienced aviators to analyse the cases. The panel comprised aviators with considerable experience in both instructing pilots and investigating accidents and incidents in safety-critical domains, including aviation, and had existing knowledge about system approaches to accident causation. Preconditions for unsafe acts were significant factors for all flights, but especially for private, training, and agricultural. Several factors at the level of unsafe supervision were associated with various preconditions for unsafe acts. For example, inadequate supervision predicted more adverse mental states and poor crew resource management, and supervisory violations predict more adverse physiological states. Poor crew resource management was predicted by inadequate supervision and planned inappropriate operations.